1. Field of the Invention
This invent on relates to a sound effect-creating device used in electronic musical instruments and the like, and more particularly to a sound effect-creating device comprising signal-modulating means, a plurality of signal-delaying means, and signal-mixing means, a combination of which can be freely selected by a player for operating the device, to thereby impart, to original musical sounds to be created by his or her performance, a so-called ensemble effect comprising various effects including the chorus effect of giving his or her listeners impressions as if they were listening to music played by a plurality of players.
2. Prior Art
In electronic musical instruments, such as electronic pianos and other electronic keyboard instruments, an artificial musical sound in an audio frequency range, which corresponds to a key of the keyboard selectively depressed by a player, is synthesized by electronic computation. In such electronic synthesis, the artificial musical sound is not only synthesized in a desired tone color and tone quality, but also often imparted with various sound effects produced according to settings selectively made for control thereof by the player via switches, volume knobs, and the like of the instrument. The ensemble effect includes a so-called chorus effect, i.e. the effect of making one player's listeners feel as if they were listening to music played by a plurality of players. As a result, the listeners can feel as if they were present in a concert hall, listening to music played by a plurality of players. Therefore, in the field of the electronic musical instruments, how to realize the ensemble effect is a very important technique in designing an instrument.
FIG. 1 shows a conventional sound effect-creating device which is adapted to artificially impart such sound effects to an artificial musical sound produced by an electronic musical instrument. In the figure, a sound effect-creating device generally designated by reference numeral 71 has delay circuits 72, 73 and 74. These delay circuits are supplied via respective signal input terminals 72a, 73a and 74a with a signal artificially synthesized by means therefor, not shown, which is representative of an artificial musical sound to be produced by the electronic musical instrument. This signal before modification for imparting the artificial sound effects to the artificial musical sound will be hereinafter referred to as "the original sound signal". These delay circuits 72, 73, and 74 have output terminals 72b, 73b, and 74b connected to input terminals 75a, 75b, 75c of a mixer 75, respectively. The mixer 75 has an output terminal 75d connected to an arithmetic unit, not shown.
According to this sound effect-creating device 71, the original sound signal is supplied via the signal input terminals 72a, 73a, 74a to the delay circuits 72, 73, and 74, separately, where the input signals are separately delayed by respective delay amounts different from each other. The resulting delayed signals are supplied to the mixer 75, where they are added up to form a mixed signal. In this case, through the above delaying operations by the respective delay circuits by delay amounts different from each other, the original sound signal is timewise separated into three signals, to that the resulting mixed signal from the mixer 75 contains three signal components which are identical in frequency but only different in phase. As a result, the resulting mixed modulation signal is in such a modified form that it will realize the ensemble effect through the chorus effect of giving listeners impressions as if they were listening to music played by a plurality of players.
Conventional sound effect-creating devices of this type are simple in their circuit configuration. However they can only create the chorus effect as the ensemble effect, and cannot create stereophonic impressions which are required to cause listeners to feel as if they were listening to music in a concert hall.